1. Field of the Invention
The present invention relates to an apparatus and a method for compensating leakage current and battery self-discharge, and more particularly, a system having such an apparatus and method.
2. Background of the Related Art
FIG. 1A illustrates a system, e.g., notebook computer, 50-1 having a recess for receiving a battery pack 40 and input 20 for receiving the voltage from an AC adapter. FIG. 1B illustrates a circuit diagram for detecting the remaining electric current of a battery. The battery pack 40 includes a battery 2, a resistor R and an electric current counter 1. When the battery is charged or discharged, an electric current flows to the resistor R and the current counter 1 measures the electric voltage generated in proportion to the electric current flowing through the resistor R. The output of the counter 1 is inputted to a micro-controller to detect the remaining electric current of the battery 2 by using the measured electric voltage.
However, such a circuit has various disadvantages. For example, the notebook uses a minute mA of electricity as stand-by electricity for operation of a control circuit when the system is turned OFF, resulting in a leakage current. The circuit can detect remaining electric current in the range of 10 mA. However, the minute mA of the stand-by electricity is too small to detect. For example, when a system is off after installing a charged battery on the system, the capacity of the battery decreases in accordance with the passage of time due to leakage current of the system. Further, the circuit cannot detect the self-leakage of the battery over time, whether the battery is connected or installed to the system.
The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background.